生态环境学报Issue(2)：283-288,6.
洞庭湖浮游植物增长的限制性营养元素研究
Nutrient limiting phytoplankton growth in Dongting Lake
摘要
Abstract
Water quality monitoring data in recent two decades in Dongting Lake showed that its eutrophication level had increased seriously. Nitrogen and Phosphorus were the major pollutants in the lake. However, the effects of composition and concentration of nutrients on phytoplankton growth in Dongting Lake has not been reported yet. The biomass of phytoplankton, forms of main nutrients and their concentrations in Dongting Lake were investigated from September, 2011 to August, 2012. Nutrient enrichment bioassay (NEB) and the correlation analysis between biomass of phytoplankton and nutrient concentration were used to detect its limiting nutrient. The results showed that the annual average concentrations of TN and TP in the lake were 1.90 mg·L-1 and 0.093 mg·L-1, respectively. Dissolved inorganic nitrogen (DIN) accounted for 87% of TN on average, while dissolved total phosphorus (DTP) accounted for 70%of TP on average. DIN was the major contributor to TN. In addition, the contribution of different forms of DIN to TN was sequenced asρ(NO3--N)>ρ(NH4+-N)>ρ(NO2--N). Soluble reactive phosphorus (SRP) was the major contributor to TP. Due to spring non-point source pollution, concentrations of TN and TP were higher in spring. In the water column, chlorophyll a (Chl a) concentration was positively related to nitrogen, and negatively related to phosphorus. The results of NEB experiment showed that addition of nitrogen could obviously boost phytoplankton biomass, and its effects increased with the continuous addition of nitrogen. While phosphorus addition did not affect phytoplankton growth. On the contrary, it sometimes inhibited growth of phytoplankton. There were no effects of interactions between nitrate and phosphorus. In summary, nitrogen was the nutrient limiting phytoplankton growth in Dongting Lake. More attention should be paid on nitrogen during the control of eutrophication in Dongting Lake.关键词
洞庭湖/浮游植物/营养限制/氮/磷Key words
Dongting Lake/phytoplankton/nutrient limitation/nitrogen/phosphorus分类
资源环境引用本文复制引用
李利强,黄代中,熊剑,张屹,田琪,何英,余建清,王琦..洞庭湖浮游植物增长的限制性营养元素研究[J].生态环境学报,2014,(2):283-288,6.基金项目
2012年湖南省环保科技计划项目 （）
